1. Field of the Invention
This invention relates to a semiconductor device and more especially to a field effect transistor on an insulating substrate.
2. Description of Related Art
Semiconductor material is usually deposited onto a substrate which has a crystalline structure compatible with the chosen semiconductor material so as to form an epitaxial layer. Selected areas of the semiconductor material are etched away to leave an array of localized islands or "mesas" in close proximity to each other. Field effect transistors are then formed in the islands of semiconductor material by conventional techniques. However, it has been found that although close proximity of the islands is possible using this technique, problems of sidewall parasitic device action occurs on the islands which leads to serious current leakage difficulties and premature turn on characteristics of the devices.